Integration

CoindPay Payments Link provides a simple, universal way to initiate and complete payments. It works across web, mobile, and serE-commerce checkout pages, SaaS dashboards, or web-based payment portals.

Environment

CoindPay provides two environments for integration and testing: Testnet and Mainnet

Testnet

App https://test.coindpay.xyz

API https://test-api.coindpay.xyz

The Testnet environment uses Ethereum Sepolia with ETH assets by default (and exclusively). It operates in Sandbox mode, which is restricted by an IP whitelist for security reasons. For more interface details, refer to Developers

To enable your test access:

• Please contact our official team @CoindPay or collaboration group to provide your fixed IP address.

• You can check your current IP at https://whatismyipaddress.com

• VPN may affect your outbound IP.

• For dev and testnet environments, we use a default vault address as the sole deposit wallet 0xbBC8f6B710359dbcdF02f9eb50Ade391890A6021 In these environments, EVM wallets are required and serve as the primary deposit option. Configuration > test.coindpay.xyz/account/wallet

Mainnet

App https://coindpay.xyz

API https://api.coindpay.xyz

• Payments support USDT/USDC on EVM and SVM networks 2. Payout assets Please confirm that your connected wallet matches the correct network in your account settings.

• On/Off-Ramps support 450+ assets across 30+ networks. When creating Ramp orders, ensure that your selected asset type matches the corresponding wallet address.

• In Mainnet wallet configuration is fully flexible — developers can specify either an EVM or SVM address as the payout primary wallet > coindpay.xyz/account/payouts

1. Create Account

Before using CoindPay, you need to create an account. This account serves as a unified identity for both your developer role and merchant enterprise.

Visit the CoindPay website and choose one of the account creation methods:

• Social Account

  • Supported social login providers (e.g. Google, X, etc.)

• Wallet

  • EVM wallet (Ethereum-compatible chains)

  • SVM wallet (Solana)

Note: Even if you sign up using a social account, you will still be required to bind a settlement wallet to complete and enable payments.

💡 Once your account is created, you will have a unified merchant identity to manage Payments Links, track orders, and manage team members.

2. Create Payments Link

A Payments Link is a convenient way to collect payments. You can generate a link and share it with customers or embed it into your applications.

Option 1: Few Products（No-code）

If you have a small number of products:

1. Create a Payments Link and provide the necessary form information at once.

2. Share the link with your customers or embed it in your website/app.

Designed for no-code integration, for creators or merchants avoiding custom development.

Option 2: Many Products（Dynamic）

If you have many products or need dynamic payment links:

1. Create a Payments Link

2. Dynamically append parameters to generate unlimited dynamic Payments Links.

3. Share or embed these links into your applications or product flows.

1. All Payments Links support dynamic parameter appending only for the parameters listed in the table below.

2. All other settings, such as payment methods, subscription type, and additional options, must be selected and configured directly in the payments form.

3. Multiple integrations

URL Parameters

You can extend the embedded checkout link by appending query parameters to the URL. This is especially useful when you want to dynamically pass metadata such as product title, description, price, images or others.

Parameter	Type	Description	Example
merchant_transaction_id	string*	Required. Unique identifier for the transaction generated by the merchant. Can be generated with randomUUID() to ensure uniqueness.	merchant_transaction_id=550e8400-e29b-41d4-a716-446655440000
signature	string?	HMAC-SHA256 hex signature generated with the merchant secret key; mandatory if price is provided.	signature=b95df8938****9fgk56
title	string?	The product or payment title displayed on the checkout page.	title=Hello
desc	string?	A short description of the product or service.	desc=Text
price	string?	Payment amount in the supported fiat or crypto currency format. Lmimits #Fiat currencies	price=29.99
currency	string?	Effective only if included in the payment link’s supported currency list; otherwise defaults to the first configured currency.	currency=EUR
images	array?	A list of image objects to display in the checkout interface.	images=[{"url":"https://cdn.example.com/item.jpg"}]
name	string?	Pre-filled consumer name (≤120 characters)	name=Elon Musk
email	string?	Pre-fill the customer's email in the checkout form.	[email protected]
payment_method	string?	Sets the default payment method for the checkout. The specified method will be automatically preselected. Supported values include card, google, apple, revolut_pay, volt_banktransfer_eur, EightBWorld_instapay, interac_gk, unlimint_pix_brl and others. Refer to Payment methods for the full and up-to-date list.	payment_method=apple
fix_payment_method	boolean?	Locks the selected payment_method and prevents changes during checkout. Recommended for channel-specific flows (e.g. iOS) to optimize conversion and payment success.	fix_payment_method=true
embed_widget	boolean?	When true, renders the payment page in compact “widget” modal.	embed_widget=true
redirect_url	string?	URL to which the user is redirected after passing the payments or ramps scenes;	redirect_url=https://coindpay.xyz/wallet
more		Please contact our Devs team for dynamic updates.

Tips

? The value is optional, * the value is required.

1. Merchant and Transaction Binding

• Each order is associated with a single merchant and a contract-defined merchant_transaction_id.

• Orders may transition through multiple statuses, but all remain tied to the same merchant_transaction_id.

• Separate or recurring orders generate distinct merchant_transaction_id values.

1. merchant_transaction_id Generation

• The merchant_transaction_id is required.

• Use randomUUID() or other encrypted ID libraries to generate a unique ID for each transaction to avoid duplicates.

• If not provided, it will not cause an error, but you may lose the ability to reliably track the order or query its status via this ID.

1. Email Consistency for KYC

• Ensure the pre-submitted email matches the one used in the subsequent KYC process.

• The email should be a user’s email address obtained in advance.

• If the email is in a valid format, it will be automatically pre-filled in the checkout form.

• If unsure, request the user to manually enter their email to prevent mismatches.

1. Price Routing Parameter

• When the price routing parameter is enabled, configure the product’s Amount Type as Fixed Amount.

• The Random Amount option is intended for tipping or donation scenarios and is not controlled by the price parameter.

• When price is not provided, the payment Link will use the amount configured in the merchant dashboard.

• When price is provided in the URL, it is treated as dynamic input and must be protected by a signature.

• Any modification to the price value without a valid signature will result in the Payment Link being marked as invalid.

1. Signature Anti-Cheating

• The signature parameter is conditionally required.

• f price is present, a valid signature must be generated and included.

• If price is absent, signature is optional.

• The signature cryptographically binds the request parameters to the merchant and prevents client-side tampering.

1. USD-Pegged Mode

• Default: USD-pegged is disabled. the amount remains uniform and can be controlled via the price parameter.

• When USD-pegged is enabled:

  • All selected fiat currencies are automatically pegged to USD.

  • Settlement amounts are calculated in real time based on current FX rates.

1. Single Fiat Currency Configuration

• If only one fiat currency is configured:

  • The product link automatically uses that currency.

  • The currency routing parameter becomes optional.

  • Passing an unconfigured currency will be ignored.

1. Multiple Fiat Currencies (USD-Pegged Disabled)

• When multiple fiat currencies are configured and USD-pegged is disabled:

  • The product link resolves to either the first configured currency or the developer-provided currency parameter (must match one of the enabled currencies).

  • Client-side currency switching is disabled; only the resolved currency is used.

1. Multiple Fiat Currencies (USD-Pegged Enabled)

• When multiple fiat currencies are configured and USD-pegged is enabled:

  • The product link resolves to either the first configured currency or the developer-provided currency parameter (must exist in the enabled list).

  • End users may freely switch between all enabled currencies.

  • Amounts remain anchored to USD, with conversions applied automatically using real-time FX rates.

1. embed_widget Routing Parameter

• The embed_widget flag enables fast checkout mode.

• It only activates if all provided parameters are valid.

Example with Parameters

import { randomUUID } from 'crypto'

const payLink = 'https://test.coindpay.xyz/pay/link/4sA2-wKhjxkCkY0W42DnQ'

const merchant_transaction_id = randomUUID() || 'others utils id'

export interface PaymentsLinkSigPayload {
  merchant_transaction_id: string
  price: string
}

export function canonicalizeSigPath(payload: PaymentsLinkSigPayload): string {
  return `merchant_transaction_id=${payload?.merchant_transaction_id}&price=${payload?.price}`
}

// Merchant payment link signature（If price is included in the URL）
// secretKey: The merchant/developer’s API Secret from the dashboard integration hooks.
export function signPaymentsLinkSig(payload: PaymentsLinkSigPayload, secretKey: string): string {
  const canonical = canonicalizeSigPath(payload)
  return createHmacSignature(secretKey, canonical)
}

// Render to your dynamic product link params
const paramsData = {
  merchant_transaction_id,  // '550e8400-e29b-41d4-a716-446655440000',
  title: 'Pro Subscription',
  desc: 'Monthly access to all features',
  price: 19.99,
  email: '[email protected]',
  // Support one or multiple cover images
  images: [ 
    { url: 'https://cdn.coindpay.xyz/stream/static/home/content/partners_bg_01.jpg' }, 
    { url:'https://picsum.photos/600/400' } 
  ],
  embed_widget: true,
})

export function getEncodePayLink(
  link: string,
  queryData?: Record<string, any>
): string {
  const url = new URL(link)

  Object.entries(queryData || {}).forEach(([key, value]) => {
    if (value === undefined || value === null) return
    url.searchParams.set(
      key,
      typeof value === 'object' ? JSON.stringify(value) : String(value)
    )
  })

  return url.toString()
}


const url = getEncodePayLink(payLink, paramsData)

// you can preview this url
console.log('url', url)

Example: Use an embed_widget link with automatic mini-widget smart flow.

The email parameter must be a valid consumer email address and will only take effect after successful validation.

https://coindpay.xyz/pay/link/nSPONbtg19ZNBAKKBA_Zu?name=Jason&[email protected]&embed_widget=true

Example: Quick payment methods limited to iOS channels

https://coindpay.xyz/pay/link/nSPONbtg19ZNBAKKBA_Zu?payment_method=apple&fix_payment_method=true

① Web Integration

E-commerce checkouts, SaaS dashboards, or any web-based payment page.

1. Embed via iFrame

Native HTML styles can be customized as needed.

You can freely customize the surrounding HTML, container styles, and transitions using TailwindCSS or your preferred styling approach.

// React component + TailwindCSS

const someCustomName = '', someCustomStyle = {}

const onIframeLoad = ()=> {} // If some scenes for iframe loading success

<iframe
  src={url}
  className={someCustomName}
  style={someCustomStyle}
  onLoad={onIframeLoad}
/>

2. Redirect to Payment Page

Customize your content area (Button, image, etc.) style

<a href={url} target="_blank">
  Pay with CoindPay
</a>

Highlights:

• ✅ No SDK required

• ✅ Instant integration

• ✅ Dynamic data and ui adaptation

② Mobile App Integration

iOS / Android / React Native / Flutter apps that need to embed or redirect to a payment flow.

1. WebView Embed

// React Native example

<WebView source={{ uri: url }} />

③ Server Integration

Automated payment creation, recurring billing, or backend-driven checkout systems.

API

Payments Link get payment product detail

GET /api/payment/payee

Payments Order get payment order detail

GET /api/payment/order

Handle the remaining workflow, using order API status and records to process callbacks automatically.

4. Account & Hooks Settings

Manage your account-related settings, including wallet bindings, event callback URLs, notifications, and developer or merchant information.

Go to More → Account/Wallet or Integration/Hooks to view and manage your developer information, webhook endpoints, and related configurations.

Developer settings

Wallet manage

Callback testing

Once your Webhooks are configured under Developer Settings → Callback URLs, CoindPay will automatically send webhook notifications to your specified endpoint whenever a payment event occurs (e.g., completed, failed, or pending).

Your server should handle these events, verify the request signature using your API Secret and update your own order database accordingly.

The following example code how to handle webhook order data in a Next.js API route.

Merchants and developers should pay special attention to verifying the x-signature request header and securely managing the private API Secret found in your Developer Hooks settings.

The API Secret is used to validate the callback signature. When a transaction status changes, CoindPay sends a webhook request containing the transaction data. If you’re using callbacks, make sure to enable signature verification to ensure authenticity.

⚠️ To verify the signature, generate an HMAC SHA-256 hash using your API Secret and the entire raw callback body as input. Because the signature is generated based on the full payload, the request body must be used exactly as received, without any modification or parsing before signature verification.

To avoid compatibility issues caused by data serialization differences across programming languages, please pay attention to how rawBody is handled in environments such as Node.js, Go, and Java.

Payments/On-Ramps Status Reference

Below is a list of possible rampStatus values returned

when rampType=buy paymentMethod=card/apple/googleand Payment methods

Status	Description
init	User opened the payment window but hasn’t entered the payment stage.
new	A new transaction has been created.
pending	Waiting for 3-D Secure verification from the user.
paid	The payer’s card has been authorized and the funds have been deposited into the processing channel. Final settlement and any conversion are subject to the issuing bank’s compliance and eligibility checks. If the bank declines, no funds will be captured.
order_scheduled	Indicates that the order has entered the processing queue. This status only reflects queue placement — it does not trigger KYC for users below the €700 threshold, and no funds are reserved.
cancelled	The transaction was canceled, usually due to timeout or user action.
order_verified_not_complete	KYC verification (required only when the user's cumulative volume exceeds €700) has succeeded. The order is queued on the exchange but not yet completed.
failed	The transaction was rejected or declined by the bank.
failed_exchange	Failed to execute the exchange for various reasons (e.g., liquidity, rate, or technical issues).
completed	✅ The merchant’s account has received the funds, and a receipt/invoice is sent to the customer’s email. This status also serves as the final indicator that the order has successfully completed.

Off-Ramp Status Reference

Below is a list of possible rampStatus values returned

when rampType=sell paymentMethod=card

Status	Description
init	User opened the payment window but hasn’t entered the payment stage.
new	A new transaction has been created.
pending	The transaction is in progress; payout processing has started.
failed	The transaction failed; the crypto amount will be returned to the user.
completed	✅ The payout has been successfully transferred to the user’s card.

Below is an example based on Node (Next.js)

// The unique ID from your front-end with the customers
const merchant_transaction_id = 'xxx' // See => Example with Parameters

// https://api.yourdomain.com/webhooks/payments/landing
import type { NextApiRequest, NextApiResponse } from 'next'
import getRawBody from 'raw-body'
import { createHmac } from 'crypto'

function createSignature(secret: string, bodyString: string): string {
  return createHmac('sha256', secret).update(bodyString).digest('hex')
}

export const config = {
  api: {
    bodyParser: false, // ✅ Disable Next.js automatic body parsing
  },
}

export default async function landing(req: NextApiRequest, res: NextApiResponse) {
  if (req.method !== 'POST') {
    return res.status(405).json({ ok: false, message: 'Method not allowed ˙◠˙' })
  }
  
  try {
    const secretKey = process.env.COINDPAY_API_SECRET_KEY as string
    
    if (!secretKey) {
      throw new Error('Missing CoindPay API SECRET KEY in env ˙◠˙')
    }

    const signatureHeader = req.headers['x-signature'] as string

    if (!signatureHeader) {
      return res.status(400).json({
        ok: false,
        message: 'Invalid signature ˙◠˙',
      })
    }
    
    // 1. Retrieve the raw request body
    const rawBody = (await getRawBody(req)).toString('utf8')
    console.log('📦 raw body:', rawBody)
    
    // 2. Verify signature (must use rawBody for verification)
    const expectedSig = createSignature(secretKey, rawBody)

    if (signatureHeader !== expectedSig) {
      console.error(`🚫 x-signature mismatch:`, { expectedSig, got: signatureHeader })
      return res.status(401).json({ ok: false, message: 'Invalid signature ˙◠˙' })
    }
    
    // 3. Parse JSON payload after successful verification
    const data = JSON.parse(rawBody)
    console.log('💎 Parsed data:', data)
  
    if (!data || !data?.id) {
      return res.status(502).json({ ok: false, message: 'Invalid payment order ˙◠˙' })
    }
    
    console.log(`✅ CoindPay payment ${data?.id}-${data?.rampStatus} callback data：`, data)
    
    // post your order data to your db, create or poll for updates
    // const payment = await prisma.payment.upsert({
    //  where: { rampId: data.id },
    //  update: {
    //    ...data,
    //  },
    //  create: {
    //    ...data,
    //  },
    // })
    ....
  } catch (error) {
    console.error(`🚫 CoindPay order data storage failed:`, error?.message)
  }
}

💡 Tips:

1. Keeping your secret key safe, don't forget add the .env file to .gitignore

2. The rampId is required, from your front-end merchant_transaction_id

3. An order is successful only when its status is completed

More tips

Testnet（Sandbox）payment card

1

Card #1

• Card Number 4444 4444 4444 3333

• Expiration Date any future date

• CVV 123

• Cardholder Name name + surname

2

Card #2

• Card Number 5555 4444 3333 1111

• Expiration Date any future date

• CVV 123 for success, 555 for fail

• Cardholder Name name + surname

If you encounter risk control or KYC interactions that affect the payment flow in the Testnet sandbox environment, you can use our official verification email: [email protected] In the regular payment environment, please use your own developer or customer email.

Fiat payments demo

43MB

CoindPay_Fiat_Payments.mp4

Open